The U.S. Army has a family of missile systems and associated laser designator systems to provide weapons known as Terminal Homing Laser Designator Weapon Systems. The success of these missile systems is directly related to the ability to precisely aim laser designator energy at a target. Error budgets which must be assessed include the pointing error of the systems, performance of the missile, stabilization of the laser spot, tracking performance of the designator, boresight of the designator, and the effects of turbulence and obscurants. Encoder readouts on the designator platform (i.e., airborne or ground laser designator) would only provide information as to where the designator was pointed, and not where the laser beam hit the target. The difference would be due to the effects of the atmosphere on the beam as well as the boresight alignment between the optical sight and the laser designator. In order to measure these errors within a few centimeters, instrumentation separate from the laser designator under test (i.e., resolver encoders within the designator) was necessary.
The most common method of measuring the position of a designator spot on a target is to use a television camera whose vidicon tube is sensitive to the wavelength of the laser energy emitted by the designator. Video data from the camera is stored on standard video tape for visual or computer analysis. Because of the sensitivity of the cameras and the time required for data reduction, other techniques of data collection and analysis are necessary.